The teen victim, known as Vasso, was pronounced dead at 9:22pm, 35 minutes after the attack which severed his jugular vein and ripped apart his voice box.

The Old Bailey heard how Ejimonye launch the savage assault ‘suddenly and without warning’ before fleeing with the huge blade.

Vasso, who lived in Newington Green, had his jugular vein and carotid artery snapped by his former friend who also cut the cartilage in his voice box before plunging the sharp knife into his lower back.

The judge heard how the victim was also carrying a knife and had previously stabbed Ejimonye – who he referred to as ‘meat head’ – in the leg.

RELATED STORIES

KILLER'S APPEAL QUASHED

Becky Watts' murderers lose challenge against their convictions and sentences

ISIS' RANDOM KILL LIST

Jihadis release details of 213 Brits plucked from social media

He's hardly De Niro!

Mark Wright follow wife and plays cop in first acting role Murder in Successville

Yorkshire Rose

Emotional tribute as thousands join Jo Cox's husband and his kids on what would've been murdered MP's birthday

'I HATE MY DAUGHTER'

Fury of grandad of Ellie Butler as he calls for public inquiry into why she was returned to her parents

MP MURDER

Jo Cox’s husband says she was murdered because of her “very strong political views”

'YOU CAN'T TRUST HER'

The killer, who describes himself as an actor and musician, was arrested one week later in Bognor Regis, West Sussex.

He admitted stabbing Vasso, but denied the charge of murder insisting he was acting in sefl-defence.

Judge Wendy Joseph handed Ejimonye a life-sentence and said he would serve at least 22 years behind bars.

She said: “To understand how he came to die, one must go back to the last day in January 2015 when Ejimonye was the victim of a knife attack – I make it absolutely clear that no one involved in this case was anything to do with that attack.

“On his own account, the defendant thereafter always walked around with a large kitchen knife and I am satisfied on his own evidence that on more than one occasion he produced that knife.

“He seems to think that was all fine because it was only produced when he felt he might be in danger – I must emphasise that is absolutely not fine.

“The choice of circles he mixed in put him in danger, he could have stayed away from those circles but because he wished to deal in drugs he continually went to these estates and continued to mix in these circles.’

She continued: “I accept that the defendant didn’t plan to meet Vasso Kakko on that evening, but in my view he knew that in going to the area he did for the purpose he did there was a good chance he would come across Vasso.

“It’s difficult to grasp the full impact of what happened the night Vasso died – I have no doubt that the impact is not only profound but permanent.

“Not only is a boy of 17 dead and his family devastated and unable to come to terms with the loss of his young life but it must also be said how much the family of the defendant himself has been affected by all of this.

Judge Joseph said she was unable to treat the murder as a deliberate intent to kill, saying: “Following the events of the month before there was a festering in your mind.

“Whilst I accept that words were exchanged between you and Vasso that evening I do not find anything that happened in the square [where Vaso fell] that night offered any sort of provocation to act as you did.”

Ejimonye remained motionless as his sentence was read out, but looked to the public gallery before being led to the cells.

Judge Joseph also gave a £500 reward to one of the victim and the killer’s mutual friends who remained at the scene to try and save Vasso while the rest of the gang had fled.

The 17-year-old, who cannot be named, called an ambulance and tried to administer first aid.

He initially told police he had seen nothing, before returning to the police station to tell them what happened.

Speaking outside of court, one of the victim’s brother’s, Bruno Kakko, said: ”We’re all devastated and we cannot change the fact that Vasso has gone and he’s never come back but we do feel that at least some justice has been done.”

During the trial, Ejimonye spoke about the incident a few weeks before the murder when Vasso stabbed him in the back of the leg.

He said: “He would always be saying ‘You don’t get money, you don’t get girls’ – degrading things.

“When we were arguing he took out his phone and tried to snap my head shape.

“He was trying to video my head shape and put it on Snapchat because I’ve got a ‘meat head’ according to him.

“I threatened to bang him in the face if he didn’t delete the video, then he got quite angry and took out his Taser.

“He threatened to Taser me with it – because I felt intimidated I got out my knife.

According to Ejimonye, Vasso left and returned with his own blade resulting in him being knifed in the leg.

This attack prompted him to plot a revenge assault.

A jury convicted Ejimonye of murder after two days of deliberations.

We pay for your stories! Do you have a story for The Sun Online news team? Email us at tips@the-sun.co.uk or call 0207 782 4368